To inhibit the unauthorized use of motor vehicles, various types of electronic interlocks have been developed and incorporated into the ignition system of vehicles. One such system, commonly referred to as PATS (Passive Anti-Theft System), utilizes a transponder embedded in the ignition key. When the key is inserted in the ignition, the vehicle ignition system generates an electromagnetic field which energizes the transponder in the key. The transponder then transmits a coded wireless signal which is received by the vehicle ignition system and decoded. If the decoded signal meets the criteria for a valid signal, the vehicle ignition system allows the vehicle engine to be started. If the decoded signal is determined to be invalid, the vehicle ignition system will prevent the engine from being started.
A variety of manufacturing difficulties have surfaced in the production of PATS keys due to the difficulty associated with incorporating a transponder into the limited amount of space occupied by a key. For example, since the orientation of the transponder within the key is important to proper operation of the electronic interlock, the manufacturing method employed should ensure a consistently accurate placement of the transponder within the key. Some transponders are encased within a glass enclosure that is susceptible to damage when exposed to mechanical shock, so consideration should be given to ensuring the survivability of the transponder after it has been formed within the key. One prior art approach to protecting the transponder and increasing its operational reliability has been to wrap a shock absorbing sleeve around the glass encased transponder before molding the transponder into the key. However, this additional manufacturing procedure increases the cost of the key. Costs and ease of manufacturability are other factors which should be considered, particularly given the fact that such keys are typically mass produced. Unfortunately, prior art approaches associated with the design and manufacture of PATS keys have been less than optimal.
Therefore, there is a need for a PATS key design and associate method of manufacture that improves upon prior art approaches.